When it comes to clothing, there are two sites I use more than any other.
Plndr.com
img src: http://1.bp.blogspot.com/_XTdCt7iI7FU/TVHauCdVCOI/AAAAAAAAA5I/BUqFL4SOiIA/s1600/hypebeast-plndr-launch.jpg
and
Jackthreads.com
img src: http://images.jackthreads.com/data/email/images/logo.jpg
Both of these sites are "Invite Only". I have that in quotation marks because you don't really need to be invited to join, but it sounds cool.
These sites have short, unannounced sales of many brands from Crooks and Castles to Michael Kors. I am more of a thrifty shopper, so these sites appeal to me. I think many companies can learn a thing or two from these websites. They offer discounts of up to 90% on many premium brand names. For example, I saw a Michael Kors jacket on Jackthreads the other day that is retail $350. It was being sold for $60.
The catch is you don't really know when sales are going to drop, so you have to check the sites often, but I think it's worth it. These "flash" sales are a great idea, companies can unload deadstock on the cheap to consumers who are a little more money conscious.
There are also benefits to current members (like myself). I can share my link to either site, and if my referral generates a sale, I get a $10 credit to whichever site was purchased from. Obviously I will close with my two share links, and if you would like to join either of these sites, feel free to use my referral!
Here is my invite to Jackthreads
and here is my invite to Plndr
Happy shopping!